Effects of Hot or Cold Water Immersion and Modified Proprioceptive Neuromuscular Facilitation Flexibility Exercise on Hamstring Length.

OBJECTIVE

To compare the changes in hamstring length resulting from modified proprioceptive neuromuscular facilitation flexibility training in combination with cold-water immersion, hot-water immersion, and stretching alone. DESIGN AND SETTING: Training-only subjects stood motionless for 10 minutes, while subjects in the cold group stood in a cold-water bath (8 degrees +/- 1 degrees C) immersed up to the gluteal fold for 10 minutes, and subjects in the hot group stood in a hot-water bath (44 degrees +/- 1 degrees C) immersed up to the gluteal fold for 10 minutes. All subjects exercised only the right lower limb using a modified proprioceptive neuromuscular facilitation flexibility protocol, consisting of 1 set of 4 repetitions. This procedure was followed for 5 consecutive days. SUBJECTS: Forty-five uninjured subjects (21 women, 24 men; age range, 18-25 years) were randomly assigned to the cold, hot, or stretching-alone group. MEASUREMENTS: Subjects were measured for maximum active hip flexion on the first and fifth days. RESULTS: Group results were assessed using a 2 x 3 analysis of variance, comparing changes in hamstring length from pretest to posttest. All 3 groups had significant improvements in hamstring length (pretest to posttest) (P <.05). However, no significant differences occurred among groups. CONCLUSIONS: No advantage was apparent in using complete hot or cold immersion to increase hamstring length in healthy subjects.